HAL® exoskeleton training improves walking parameters and normalizes cortical excitability in primary somatosensory cortex in spinal cord injury patients

Abstract

BackgroundReorganization in the sensorimotor cortex accompanied by increased excitability and enlarged body representations is a consequence of spinal cord injury (SCI). Robotic-assisted bodyweight supported treadmill training (BWSTT) was hypothesized to induce reorganization and improve walking function.ObjectiveTo assess whether BWSTT with hybrid assistive limb® (HAL®) exoskeleton affects cortical excitability in the primary somatosensory cortex (S1) in SCI patients, as measured by paired-pulse somatosensory evoked potentials (ppSEP) stimulated above the level of injury.MethodsEleven SCI patients took part in HAL® assisted BWSTT for 3 months. PpSEP were conducted before and after this training period, where the amplitude ratios (SEP amplitude following double pulses - SEP amplitude following single pulses) were assessed and compared to eleven healthy control subjects. To assess improvement in walking function, we used the 10-m walk test, timed-up-and-go test, the 6-min walk test, and the lower extremity motor score.ResultsPpSEPs were significantly increased in SCI patients as compared to controls at baseline. Following training, ppSEPs were increased from baseline and no longer significantly differed from controls. Walking parameters also showed significant improvements, yet there was no significant correlation between ppSEP measures and walking parameters.ConclusionsThe findings suggest that robotic-assisted BWSTT with HAL® in SCI patients is capable of inducing cortical plasticity following highly repetitive, active locomotive use of paretic legs. While there was no significant correlation of excitability with walking parameters, brain areas other than S1 might reflect improvement of walking functions. EEG and neuroimaging studies may provide further information about supraspinal plastic processes and foci in SCI rehabilitation.

The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review

“…Furthermore, some believe this mechanism leads to increased patient mobility when not wearing the exoskeleton, even in patients with chronic SCI. 3,23 There is a certain optimism that exoskeletons, primarily mobile exoskeletons used as rehabilitation devices (e.g., HAL, and to some extent, Ekso-Bionics), have potential to improve walking patterns after the device is removed. 3,[23][24][25][26][27][28] In our study, adverse events were infrequently reported in literature, with only one trial indicating skin irritation or abrasion from exoskeleton training.…”

Functional Neurorehabilitation using the Hybrid Assistive Limb (HAL): A First Experience in the United States

“…® is postulated to aid cortical plasticity and the restoration of spinal reflex circuits through the recruitment and repeated use of remaining somatosensory afferent pathways and corticospinal tracts [12,20]. Patient 3 experienced a decline in performance in the 6MWT and TUG test between the 12 week and 6 month follow-up.…”

“…This may evidence regression without HAL ® training. Furthermore, electrophysiological data has demonstrated a normalization of primary somatosensory cortex activation, the disinhibiting and reorganization of which is a staple of spinal cord injury [12].…”

“…Furthermore, these studies have shown that training with HAL ® improves quality of life, decreases neuropathic pain and increases patient's functional mobility, over-ground walking, muscle strength and motor function in and out of HAL ® [11][12][13][14].…”

Tecnología De Asistencia: Exoesqueletos Robóticos en Rehabilitación

“…Adicionalmente, se reporta el aumento en variables cinéticas y cinemáticas de la marcha tales como: velocidad, distancia, longitud de zancada, ancho de paso, cadencia (Kozlowski, Bryce, & Dijkers, 2015;Yang, Asselin, Knezevic, Kornfeld, & Spungen, 2015). De hecho, el uso de exoesqueletos aumenta la habilidad para mantener el balance mientras la persona está en posición bípeda, aumenta la propio cepción además de mejorar los traslados y la descarga de pesos en extremidades inferiores, aumen ta en rango de movimiento en cadera, rodilla y cuello de pie (Aach et al, 2014;Asselin, Avedissian, Knezevic, Kornfeld, & Spungen, 2016;Esquenazi, Talaty, Packel, & Saulino, 2012;Sczesny-Kaiser et al, 2015).…”